You can sand the chrome and use a metal etching primer prior to the color coat. Start with something like 280 to 300 grit paper, preferably wet and work down to 400. Lay on a couple of coats of the etching primer, sanded between coats then go for the color. You want the chrome roughed up so it looks like the back side of aluminum foil. No shiny areas, anywhere. Any shine will be where the paint can start to peel and lift away.
Be careful with any masking if you're doing multiple colors. When the color coat is dry spray on a couple of coats of a fuel (gasoline) resistant clear.
Good luck.
Tom
